But everyone’s circumstances are different so it’s completely irrelevant that you or other people are able to do xyz on a lower income.
You went interest only on your mortgage. Great. Except mortgage costs are currently sky high so for some people, even moving to interest only will still represent a significant % of their net pay.
You mention you had savings prior to having children. Amazing. You do know that not everyone is able to do that?
I won’t ask your age but assume you didn’t have to make hefty Student London repayments.
I could go on. There are probably a dozen other things specific to your life circumstances that do not apply to other people and which mean they cannot manage on a lower take home pay than e.g. £5k a month. It doesn’t matter if you were able to do it because your life is different from theirs.
We have friends with a high household income who have a child with significant additional needs which 2 different nurseries and an experienced childminder could not meet. So they employ a nanny and pay her ££££ a month plus other employer expenses. They live in expensive London because they have access to their network of other families with disabled children, therapy and specialised help for their DC. Finding a nanny with the skills and experience to look after child took months and if they move away they will likely lose her.
The Band 5 nurse…well a close relative is a nurse. She lives in Romford with her DC, pays £1400 rent for a 1-bed and earns (I think) just under £30k a year which I think is Band 5. She sleeps on a couch. Romford is apparently one of Greater London's cheaper areas so our friends with the disabled child could move there…except it isn’t that cheap at all. They need a 3 bed house which currently rent for around £2.5k - £3k a month in what was once a very affordable area.
The simple fact is that for millions of people there are no easy, magically cheaper options available to them and the fact they earn a lot doesn’t change that fact. You seem very unsympathetic to the plight of people whose lives differ from yours.